Heat sink

Abstract

A heat sink includes a base plate; a cover overlapping the base plate; fins, each having a plate-like shape projecting from the base plate in a direction perpendicular to the base plate, located between the base plate and the cover; one or a plurality of first fin groups composed of a plurality of the fins arranged with a gap therebetween in a first direction; and one or a plurality of second fin groups composed of a plurality of the fins arranged with a gap therebetween in the first direction, and adjacent to the first fin group with a gap therebetween in a second direction. Positions in the first direction of the fins belonging to the second fin group are displaced with respect to positions in the first direction of the fins belonging to the first fin group. Each of the fines has an S-shape.

What is claimed is: 
     
       1. A heat sink comprising:
 a base plate; 
 a cover overlapping the base plate; 
 fins, each having a plate-like shape projecting from the base plate in a direction perpendicular to the base plate, the fins being located between the base plate and the cover; 
 one or a plurality of first fin groups composed of a plurality of the fins arranged with a gap therebetween in a first direction parallel to the base plate; and 
 one or a plurality of second fin groups composed of a plurality of the fins arranged with a gap therebetween in the first direction, and adjacent to the first fin group with a gap therebetween in a second direction parallel to an inflow direction of refrigerant and perpendicular to the first direction, wherein 
 a longitudinal direction of the fins is along the second direction, 
 positions in the first direction of the fins belonging to the second fin group are displaced with respect to positions in the first direction of the fins belonging to the first fin group, 
 each of the fins has an S-shape having a first curved portion which is curved to project to one side in the first direction, and a second curved portion which is curved to project to another side opposite to the one side in the first direction, 
 the gap between the fins in the first group and the second fin group has an inlet portion and an outlet portion in the second direction, which are located on one line perpendicular to the first direction, and 
 a pitch P and a distance R are set 1/10≤R/P≤ 5/10, where the pitch P is a distance, in the first direction, between centers of gravity of the fins adjacent to each other in the first fin group and between centers of gravity of the fins adjacent to each other in the second fin group, and the distance R is a difference, in the first direction, between a center of gravity of the fin in the first fin group and a center of gravity of the fin in the second fin group closest to the fin in the first fin group. 
 
     
     
       2. The heat sink according to  claim 1 , wherein the pitch P and the distance R are set ⅕≤R/P≤⅖. 
     
     
       3. The heat sink according to  claim 1 , wherein the pitch P and a length G are set G>P, where the length G is a distance between the fins in the first fin group and the fins in the second fin group. 
     
     
       4. A heat sink comprising:
 a base plate; 
 a cover overlapping the base plate; 
 fins, each having a plate-like shape projecting from the base plate in a direction perpendicular to the base plate, the fins being located between the base plate and the cover; 
 one or a plurality of first fin groups composed of a plurality of the fins arranged with a gap therebetween in a first direction parallel to the base plate; and 
 one or a plurality of second fin groups composed of a plurality of the fins arranged with a gap therebetween in the first direction, and adjacent to the first fin group with a gap therebetween in a second direction parallel to an inflow direction of refrigerant and perpendicular to the first direction, wherein 
 a longitudinal direction of the fins is along the second direction, 
 positions in the first direction of the fins belonging to the second fin group are displaced with respect to positions in the first direction of the fins belonging to the first fin group, 
 each of the fins has an S-shape having a first curved portion which is curved to project to one side in the first direction, and a second curved portion which is curved to project to another side opposite to the one side in the first direction, 
 the gap between the fins in the first group and the second fin group has an inlet portion and an outlet portion in the second direction, which are located on one line perpendicular to the first direction, and 
 the pitch P and a length G are set G>P, where the length G is a distance between the fins in the first fin group and the fins in the second fin group and the pitch P is a distance, in the first direction, between centers of gravity of the fins adjacent to each other in the first fin group and between centers of gravity of the fins adjacent to each other in the second fin group.